My view: Mine expansion requires monitoring

Recently, Salt Lake County Mayor Peter Corroon did precisely the right thing when he halted discussions about a troubling land deal with Rio Tinto.

A few weeks ago, residents in the southwest corner of the Salt Lake Valley were informed that Mayor Corroon and the Salt Lake County Council contemplated selling half of their Rose Canyon Ranch gem to Rio Tinto. Salt Lake County purchased the ranch in 2007 to protect and secure the open space for current residents, as well as our future generations.

The connection between Rose Canyon Ranch and Rio Tinto's plans to expand the Bingham Canyon Mine became immediately apparent. The expansion plan, known as the Cornerstone Project, would increase the footprint of the mine 34 percent, expand the south side of the pit 1,000 feet south and add millions of tons of waste rock south of the current waste rock pile. Rose Canyon Ranch is directly in the path of this expansion.

What is extremely concerning about this plan is the potential contamination of air, water and land. Salt Lake County owns the surface rights to 832 acres of pristine open space. Is this ranch now to become a dumping ground?

In two separate meetings, Rio Tinto stated they plan on exploratory drilling through our main aquifer under the ranch area, to a depth of two to three thousand feet. The southwest corner of the Salt Lake Valley gets its water from that aquifer. The aquifer services unincorporated Salt Lake County, Herriman, Bluffdale and Riverton. Rio Tinto used the antiquated General Mining Act of 1872 to obtain subsurface minerals rights not only under the ranch but also under homes in the neighboring area.

It is known that waste rock hauling and dumping contributes to environmental issues in the Salt Lake Valley. Each truck dumps approximately 270 tons of waste rock. Rio Tinto stated they will increase the number of water trucks for dust control, for watering the roads only. Rio Tinto cannot water the dust from dumping because this would destabilize the already unstable pit walls.

Rio Tinto might also mine using a shaft from the ranch or tunnels from the south side of the pit. Whatever the method used to exploit this claim, the aquifer contamination and waste rock dumping are extreme concerns that have been voiced by residents and the Herriman City Council. Moreover, could this expansion permanently close Butterfield Canyon? The canyon sits between the current mining area and the proposed expansion.

Rio Tinto offered to pay $1 million more than the county paid for the ranch. Why would Rio Tinto be so generous? Mayor Corroon tried negotiating with Rio Tinto for frequent air and water sampling, dumping restrictions, public access and other issues as part of the sales contract. My understanding is that Rio Tinto is unwilling to negotiate.

As of Dec. 23, 2010, Mayor Corroon ceased discussions of Ranch sale with Rio Tinto. This is good news to the residents in the southwest corner of the valley and Salt Lake County as a whole.

From Salt Lake County's press release: "The mayor acted after Kennecott declined to be contractually obligated to monitor air and water quality in and around mining operations planned for the property." Also: "Residents of Herriman and High Country Estates asked for assurances that their water supply will not be negatively affected since their aquifers are in the vicinity of the area targeted for mine exploration and drilling activities. … I will not sign a contract without agreement for air and water monitoring," says Mayor Corroon.

Bill Coon is a resident of unincorporated Salt Lake County west of Herriman.